Mailbox Layer API to verify emails

I have a developer that has written a Python script that connects to the Mailbox Layer API to verify emails. I need someone to build me a backend that includes an authentication system so that I can separate paying users that have access to the tool versus users that don’t (login/logout). The backend will need to connect to a MySQL database and keep track of sessions and other data related to the user and activity. The frontend will be a very simple one page UI similar to [login to view URL] where a user can input the first name, last name and domain name for a user or upload a CSV and return the emails associated with those users. Down the line, I will also have another Python script that pulls personal and company information for a particular person. The front end for this will be a Chrome extension.